Anticipation Powerful in Human Memory

Anticipation of a fearful experience can enhance the memory of it after it has happened, a new study has shown.

Scientists already know that memories of disturbing emotional events are more vivid and deeply imprinted in people's minds than everyday events.

And now new research from the University of Wisconsin-Madison reveals that the anticipation of a fearful experience fires up two memory-forming regions of the brain before the event has even happened.

This then results in anticipation playing an important role in how fresh a memory remains in people's minds.

Published in the Proceedings of the National Academy of Sciences, the findings of the brain imaging study are thought to have significant implications for the treatment of psychological conditions such as post-traumatic stress disorder (PTSD) and social anxiety.

Lead author Kristen Mackiewicz said: "The main motivation for this study was a clinical one, in terms of understanding and applying knowledge about memory so that we can better inform the treatment of disorders that have a large memory component, like PTSD."

Thirty-six healthy volunteers had images taken of two regions in the brain, the amygdala and the hippocampus, while they were shown dozens of violent images. Signals were given before the violent images to indicate that they would come next, rather than a neutral image.

The volunteers were then quizzed 30 minutes later on how well they remembered the images.

Scans of the brain areas showed that the "more activated the amygdala and hippocampus had been during the anticipation [of the pictures], the more likely it was that a person would remember more of them right away", according to senior author Jack Nitschke.

The study's authors conclude that future research would look at ways in which the anticipatory response could be dampened so that people do not evoke negative memories so easily.